Why does the package imported into the PCB have no flying leads?

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Why does the package imported into the PCB have no flying leads? [Copy link]

There are generally three situations when there are no flying wires after importing the PCB: 1. The connection in the schematic diagram is not drawn well, which is a rare situation. 2. The pin number in the schematic diagram does not correspond to the PCB package number, which is a very common situation. For example: the PCB package is someone else's, and they use A and K to represent pads 1 and 2, but when you draw the schematic library, you use 1 and 2, which causes the PCB package to be imported but there is no flying wire. Common components that usually make mistakes are: transistors, LEDs, MOS tubes, adjustable resistors and other components. 3. The third situation is that even the PCB package is not imported, so there is definitely no flying wire. This situation is usually caused by the package name in the PCB package not corresponding to the package name in the schematic (if the PCB library has this package, it is another matter if it does not). The following picture shows an example. The wiring connection of the transistor in the schematic diagram is normal. But when it is imported into the PCB, it is found that there is no flying wire connection on pin 1, as shown in the following figure. When the schematic is imported into the PCB, there will be an error, and it is generally difficult for novices to understand what this means. So skip this. This is the second of the three situations above, so how do you check whether the pin number is correct? Please continue reading. Double-click the transistor, and the following dialog box will pop up. We click where the arrow in the figure points. After clicking, the following dialog box will pop up. We can see that the last one in the first column, C should be 1, but it is written as C. We can see from the top that the pin number of the transistor in the PCB is 1, so the PCB package cannot be recognized and an error is reported, and there will be no flying wire on the 1st pin of the transistor in the PCB. We change C to 1, save the schematic, and import it into the PCB to solve the problem. How to modify it? You can modify it directly in the picture below. It is recommended that you modify it in the schematic library, because when you modify it in the picture below, you can only modify the current one. If you use it later, there will be errors. Of course, in addition to modifying the schematic library, the PCB library can also be modified. The modification method will be discussed later, so I will not go into details here. The third of the three situations occurs, there is no package or the name is wrong. The error shown in the figure below will appear. Check the package, change the error, and import it again.

ddllxxrr

Well written, thumbs up

chenzhufly

Looks like a big project